Kose puhasti Wastewater Treatment Plant, Kose, Estonia

Kose puhasti is a municipal wastewater treatment plant located in Kose, Harju County, Estonia. The facility serves a population of around 1,080 residents and is designed to handle up to 3,000 m³ of wastewater per day, with an average discharge volume of 248.83 m³/day. The plant employs advanced treatment processes, which go beyond the secondary treatment standards typically required under the EU Urban Waste Water Treatment Directive (91/271/EEC). For small agglomerations like Kose (under 2,000 population equivalent), the directive mandates appropriate treatment, and the advanced level here indicates a high standard of nutrient removal and effluent quality. The treated effluent is discharged into local watercourses that eventually drain into the Baltic Sea via the Gulf of Finland. The plant plays a key role in protecting the region's surface waters and groundwater from nutrient pollution, supporting the ecological health of the downstream aquatic environment.

The plant discharges into the local river system, which flows through the Harju County landscape and ultimately reaches the Baltic Sea via the Gulf of Finland. This coastal region is ecologically sensitive, supporting diverse aquatic life and serving as a habitat for migratory fish species. Advanced treatment helps reduce nutrient loads that could otherwise contribute to eutrophication in the Baltic Sea.